First elected as a U.S. Senator from Wisconsin in 1946, few noticed Joseph McCarthy during his first three years in the Senate. All that changed when in February 1950 he made a bombshell speech. Addressing the Republican Women’s Club of Wheeling, West Virginia, he announced that he had evidence that in spite of the Truman administration’s efforts to eliminate disloyal elements from government service 205 members of the Communist Party continued to work for the State Department.

Two days later McCarthy sent a letter to President Truman in which his estimate of the number of communists in the State Department was reduced to 57. At the same time, he demanded that the president provide him with the findings of the State Department’s Loyalty Board (created in March 1947 as part of Truman’s Loyalty Program), suggesting that if he failed to do so it would suggest that the Democratic Party was “the bedfellow of international communism.”

Under normal circumstances McCarthy’s accusation might have been dismissed as nonsense, but the circumstances of early 1950 were hardly normal. Domestically, Alger Hiss had just been convicted, and less than a year earlier the Federal Bureau of Investigation had issued a list of American celebrities who belonged to the Communist Party. Moreover, ominous developments were taking place outside the country—within the past six months China had become communist, and the Soviet Union had successfully tested an atomic weapon. It seemed as though the country might be losing the Cold War, and McCarthy’s charges offered an explanation of why that might be so.

Among those unimpressed with McCarthy was Truman, who in a press conference in March told reporters that the Wisconsin Republican was “the greatest asset that the Kremlin has.”